Azure Cloud, App Service, Key Vault & Application Insights Masterclass

# Install packages
dotnet add package Azure.Extensions.AspNetCore.Configuration.Secrets
dotnet add package Azure.Identity

# Create Key Vault and add secret via Azure CLI
az keyvault create --name "MyAppKeyVault" --resource-group "MyRG" --location "EastUS"
az keyvault secret set --vault-name "MyAppKeyVault" --name "SqlConnectionString" --value "Server=..."

// Program.cs — Azure Key Vault with Managed Identity (no credentials needed!)
var keyVaultUri = new Uri(builder.Configuration["KeyVaultUri"]!);

builder.Configuration.AddAzureKeyVault(
    keyVaultUri,
    new DefaultAzureCredential()); // Uses Managed Identity in Azure, dev credentials locally

// Now access Key Vault secrets like any config value:
var connectionString = builder.Configuration["SqlConnectionString"];

// dotnet add package Microsoft.ApplicationInsights.AspNetCore

// Program.cs — One-line registration
builder.Services.AddApplicationInsightsTelemetry();

// appsettings.json
{
  "ApplicationInsights": {
    "InstrumentationKey": "your-key-here"
  }
}

// Custom telemetry in your services
public class ProductService
{
    private readonly TelemetryClient _telemetry;

    public ProductService(TelemetryClient telemetry) { _telemetry = telemetry; }

    public async Task CreateProductAsync(Product product)
    {
        _telemetry.TrackEvent("ProductCreated", new Dictionary<string, string>
        {
            ["ProductId"]   = product.Id.ToString(),
            ["ProductName"] = product.Name,
            ["Category"]    = product.Category
        });
    }
}

// dotnet add package Azure.Storage.Blobs

public class BlobStorageService
{
    private readonly BlobContainerClient _container;

    public BlobStorageService(IConfiguration config)
    {
        var client = new BlobServiceClient(config["AzureStorage:ConnectionString"]);
        _container = client.GetBlobContainerClient("product-images");
        _container.CreateIfNotExists(PublicAccessType.Blob);
    }

    public async Task<string> UploadImageAsync(IFormFile file)
    {
        var blobName = $"{Guid.NewGuid()}{Path.GetExtension(file.FileName)}";
        var blobClient = _container.GetBlobClient(blobName);

        await using var stream = file.OpenReadStream();
        await blobClient.UploadAsync(stream, overwrite: true);

        return blobClient.Uri.ToString(); // Public URL of uploaded image
    }
}